Explain why fatty acids are insoluble in water in terms of the structure of fatty acids.?

Answer 1

Fatty acids have long hydrocarbon chains that are nonpolar, meaning roughly equal sharing of the electrons among the bonds between carbon atoms. Water is a polar substance where there is very unequal sharing of the electrons.

Non-polar substances do not dissolve very well in polar substances (such as water).

Answer 2

Normal fatty acids exhibit appreciable solubility in water compared to the corresponding hydrocarbons due to the presence of the polar carboxyl group. The first members of the saturated fatty acid series are miscible with water in all proportions at room temperature.

Fatty acids are merely carboxylic acids with long hydrocarbon chains. The hydrocarbon chain length may vary from 10-30 carbons (most usual is 12-18). The non-polar hydrocarbon alkane chain is an important counter balance to the polar acid functional group. In acids with only a few carbons, the acid functional group dominates and gives the whole molecule a polar character. However, in fatty acids, the non-polar hydrocarbon chain gives the molecule a non- polar character.

Answer 3

Water is very polar with a lot of Hydrogen bonding. Fatty acids are non-polar. That is why pharmaceutical companies use a lot of organic solvents and hydrocarbons in the manufacture of drugs.